Liquid products, particularly household and fabric care compositions such as dishwashing soap, hand soap, and surface cleansers, are a popular choice among consumers. Generally such liquids are sold within plastic containers. These plastic containers oftentimes have a body with a larger bottom end and an opposing tapered neck connecting to a smaller top end. The larger bottom end allows for a container to stand upright on a surface such as for storage purposes. The smaller top end can be attached to a cap or to a dispenser for dispensing purposes. The smaller top end is oftentimes a round opening. This opening is usually relatively small in area to make it easier for a consumer to control the amount of liquid that poured out of the container. During the manufacturing process of the container holding the liquid, manufacturers will use a container filling system to dispense liquids through the opening into the container.
High-speed container filling systems are well known and used in many different industries. In many of the systems, the containers are filled through a series of pumps, pressurized tanks and flow meters and/or valves to help ensure that the correct amount of liquid is dispensed into the containers. These pumps, pressurized tanks, flow meters, and/or valves are typically connected to a nozzle having an opening above or within the container opening. The liquid flows through this nozzle opening into the container. Manufacturers are continually looking for ways to increase the volumetric flow rate of the liquid during the filling process, which in turn increases the speed and efficiency of the process of filling containers with liquids.
Filling containers through small top openings can be challenging to do quickly due to size constraints of the top opening and the neck coupled with the rheological properties of the liquid. To compensate for slower filling speeds associated with conventional size, single orifice nozzles, the nozzle orifice size can be made larger, allowing higher volumetric flow rates and faster filling cycles. However, when filling containers, especially at high volumetric flow rates, the large opening can create a surge of liquid at the end of the filling event that can cause the liquid in the container to splash in a direction generally opposite to the direction of filling and often out of the container being filled. This is especially true for lower viscosity liquids such as hard surface cleaners, examples of which are under the tradenames MR. CLEAN, SWIFFER WETJET, and VIAKAL manufactured by The Procter & Gamble Company. Higher viscosity liquids, such as dishwasher liquids, such as, for example, those sold under the tradename DAWN and laundry detergents such as, for example, those sold under the tradenames TIDE and GAIN manufactured by The Procter & Gamble Company may result in a filament or string that forms and hangs down from the filling nozzle at the end of the filling event, this filament or string taking some time to break up after flow to the nozzle ceases.
Alternatively, a nozzle can have a multitude of smaller openings through which liquid flows during the filling process. However, there is a limitation on the number and size of openings that can be placed in one constrained area. If the openings are spaced too close to one another, the liquid may join together to form one stream, which in turn, can result in the same aforementioned stringing and/or splashing problems. If the openings are spaced too far apart, fewer openings will be able to fit on the nozzle surface resulting in reduced volumetric flow rate and slower filling speed. Stringing and splashing can waste liquid, contaminate the outer surface of the container and/or contaminate the filling equipment itself. Having a nozzle with too large an opening or a nozzle with openings spaced too closely to one another may result in an increase in the velocity of the liquid. An increase in the velocity of the liquid stream may result in greater entrapment of air which in turn causes undesirable foaming of the liquid near the impinging jet when the liquid hits the bottom surface of the container. In order to mitigate or avoid splash-back and air entrapment, manufacturers can use oversized containers to provide enough head space to prevent any back-splash from exiting the container. This creates waste in terms of the amount of material used to make the containers, which can be costly, and can result in containers that appears to be less than completely filled. Manufacturers also slow the filling line rate down to compensate for splash-back and for air entrapment which may result in a decrease in number of containers that can be filled on a single filling line during a given time.
In view of the above, there is a continuing unaddressed need for nozzles for filling machines that are capable of quickly filling a succession of containers with liquid by increasing the volumetric flow rate of the liquid while lessening or avoiding splashing, stringing, dripping, and foaming of the liquid, and that are capable of cleanly shutting off the flow of liquid between containers to avoid dripping of the liquid outside of the containers at the end of a filling event.